In mice, a small region of the hippocampus known as CA2 (green) is essential for social memory, the ability of an animal to recognize another of the same species. (Credit: Steven Siegelbaum, Columbia University Medical Center)

The human brain, just a 3-pound mass of tissue, has the ability to remember a lifetime of experiences. Our short-term, or working, memory serves as a kind of mental workspace, transiently retaining new information that helps guides our thoughts and actions. Long-term memories, which are retained indefinitely, can be implicit, or unconscious, such as some motor skills that have been learned over time. They can also be explicit, meaning that retrieving stored information about people, places and things requires conscious effort.

Some of the central questions in memory research include: How and where do we make new memories? How are they sustained for long periods of time? How are memories stored and retrieved? What can be done to prevent memory loss? And can our memories be manipulated? Scientists such as Eric Kandel, Kavli Professor of Neuroscience at Columbia University, have pieced together many of the chemical and structural changes in brain cells as different types of memories are encoded and retained, and have also identified many of the proteins involved. And very new research in mice suggests that false memories can be created artificially, raising hope that new treatments will be developed to help individuals with traumatic memories and other memory-related disorders.

For the first time, scientists have watched sleep transform the brain. The research confirms a long-standing theory about the value of sleep—and helps explain why sleep deprivation messes with our ability to remember. Four neuroscientists—Chiara Cirelli, Graham Diering, Richard Huganir and Ken Paller—discuss two breakthrough sleep studies.

In a roundtable discussion, three leading scientists in the fields of neuroscience, brain imaging and cell biology weigh in on what it will take to find a cure for Alzheimer's and related neurodegenerative disorders.

KIBS researchers aim to crack the code of the mammalian brain, starting with one of its memory networks. Neuroscientist Attila Losonczy discusses the ambitious plan and why it has received the support of President Obama’s BRAIN Initiative.

The winners of the 2014 Kavli Prize in Neuroscience – Brenda Milner, John O’Keefe and Marcus E. Raichle – discuss what led them to study memory and cognition and the challenges they faced in getting their discoveries about the brain accepted.

For most of us, a declining memory is a normal consequence of growing old. But why? What’s happening in the brain that causes age-related memory decline, and is there anything we can do to slow this decline?